1. Field of the Invention
The present invention relates generally to powered, automated door systems, and more particularly to a laterally symmetrical, bi-folding door assembly having four folding panels comprising a jamb panel and a generally central panel to each side of the center of the door opening. The jamb panels are each approximately one sixth of the width of the door opening, with the central panels each being about one third of the door opening width. The present bi-folding door system includes various novel features, including means allowing the doors to be opened manually without disengaging the doors from their drive tracks or requiring the door system to be reset after such manual operation.
2. Description of the Related Art
Automatically actuated door systems are quite popular in many businesses and other establishments, due to their convenience for customers and others who have occasion to use the doors. Such automated doors can assist in the conservation of energy and maintenance of the interior climactic environment of the building by means of their automated closure systems, and may also provide greater security than conventional manually actuated door systems, regardless of their configuration.
A large number of different automated door configurations have been developed as a result of the above automated door needs, with various types of multiple panel doors which open and close in an xe2x80x9caccordion stylexe2x80x9d operation being quite popular due to their relatively compact configuration when opened. It will be seen that such an arrangement requires that the door panels have a width of only half that of the door opening, where two equal width panels are used. This greatly reduces the space which would otherwise be required for a conventional, side hinged door comprising a single panel. Even more opening space can be saved by providing greater numbers of door panels, with multiple panels disposed to each side of the center of the door opening in a symmetrical array.
However, most multiple panel hinged door configurations have equal size panels. It will be seen that with the outermost jamb panels hinged to the door jambs to each side of the door opening, that the entire width of the door panels must swing to one side (i.e., inside or outside) of the door opening. This arrangement detracts greatly from the otherwise compact opening configuration which might be provided by centering the opened door panels within the door opening. Nevertheless, most manufacturers of multiple: panel doors prefer such equal panel door configurations, as such equal size door panels simplify the geometry of the actuating mechanism and the installation of the door assembly. This is particularly true when considering the various actuating systems of the prior art, where relatively complex mechanisms have been used to open the panels or to draw the panels to a closed position.
Another problem with such multiple panel, laterally and arcuately moving door panels, is that of providing for emergency egress in the event of an electrical power failure. Federal regulations require that any powered, automated door system be capable of being opened by applying a force of no more than a few tens of pounds, close to the center of the door(s). Generally, most automated door manufacturers have responded to this requirement by providing a relatively weak attachment point or link between the center area of the door at its top, and the associated track and drive structure. Thus, a person can push on the center of the door and break the door loose from its attachment in the event of an emergency and loss of power for the door. However, such systems require the door to be reinstalled with its retainer, before the automated function can be reactivated.
Accordingly, a need will be seen for an automated multiple panel door system which overcomes the above problems and further provides a relatively straightforward mechanism for doing so. The present bi-fold door system essentially comprises symmetrical, left and right jamb and primary panels, with the jamb panels having half the width of the primary panels. The jamb panels are hinged to the door jamb or frame along their jamb edges, while the primary panels pivot arcuately about their vertical centerlines as they are moved laterally in the door frame. This configuration results in only about one sixth of the total door width disposed to each side of the door frame when the panels are opened, thus saving substantial room which would otherwise be required for opening the doors.
The present bi-fold door system also responds efficiently to the requirement for emergency egress, with the central edges of the two center or primary panels initially swinging outwardly as the doors are actuated for opening. A manual force of less than thirty pounds is required for a person to push the two central panels open, against the mechanical resistance of the drive belt, transmission, and motor connected thereto. The present bi-fold door retains the mechanical relationships between all components when opened manually, and does not require a person to reset or realign any components after manual opening. Moreover, the present bi-fold door introduces a much more elegant mechanical means for xe2x80x9cbreaking,xe2x80x9d i. e., deflecting the plane of the door from the plane of the door frame, at initial opening, in order to reduce linear stresses on the door track drive system.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,106,544 issued on Aug. 15, 1978 to Guy E. Dixon et al., titled xe2x80x9cElectrically Operated Folding Partition,xe2x80x9d describes an asymmetrical multiple panel folding door having a single half width jamb panel hinged to one jamb, with a series of full width folding panels extending therefrom and across the entire door opening when the door is closed. Dixon et al. require a relatively complex actuation system which initially pulls the doors more tightly closed to align the hinges, before the door may be opened. Positive closure is provided by an essentially opposite action, in which inertia moves the doors past the aligned hinge position and the drive motor then applies a slight opening force to compress the panels along their coplanar disposition within the door frame. Dixon et al. are silent regarding manual opening of their door system, but it appears that the Dixon et al. door system cannot be completely opened by a push upon the central panel(s) in the event of a power failure, as the lead panel is held in a coplanar orientation with the door frame by means of a pair of guides. In contrast, the present bi-fold door invention is symmetrical, and may be completely opened manually by pushing on the central panel(s) of the assembly. Moreover, the motorized opening and closing system of the present door system is greatly simplified over that of the Dixon et al. system, obviating any requirement for additional slight actuating motions to initiate is door opening or closing.
U.S. Pat. No. 4,534,395 issued on Aug. 13, 1985 to William F. Carroll, titled xe2x80x9cFolding Door,xe2x80x9d describes a bi-fold door system wherein the jamb panels are somewhat wider than half the width of the primary panels. This results in the primary panels being asymmetrically disposed within the door frame when the door is opened, unlike the present bi-fold door system. Moreover, as the hinge lines between the two panels on each side fold outwardly, the center edges of the two primary panels move inwardly during normal operation; they cannot be pushed outwardly during manual operation, without disconnecting the doors from their automatic operating mechanism. A mechanic or other person would be required to reset the two primary panels in their ball detent retainers, after manual opening of the Carroll door system. In contrast, the present bi-fold door system moves the hinge lines between each jamb panel and main panel inwardly, thus displacing the central edges of the two central panels outwardly in normal operation. In the event of a power failure, the present bi-fold doors may be quickly and easily opened by pushing outwardly upon the central edges, whereupon the doors travel in their normal motion without being displaced from their actuating mechanism. The automatic operating mechanism of the present door system automatically repositions the doors when power is restored, with the present door system thus requiring no additional intervention to restore normal powered, automated operation after a manual operation.
U.S. Pat. No. 4,887,659 issued on Dec. 19, 1989 to Floyd D. West, titled xe2x80x9cHigh Speed Folding Door,xe2x80x9d describes a doorway formed of a series of loosely interconnected vertical slats, bearing more resemblance to vertical blinds than to a tightly sealing door. The West door is adapted for use with loading docks and the like, to protect the interior from any weather extremes occurring outside. While West provides for emergency egress by separating the breakaway straps which laterally connect the panels together, the panels do not remain connected as do the hinged together door panels of the present bi-fold door invention. The West panels must be reconnected after separation whereas the present door panels are permanently connected together on each side of the door opening.
U.S. Pat. No. 4,961,454 issued on Oct. 9, 1990 to Paul J. Reilly, Jr. et al., titled xe2x80x9cInsulated Folding Door,xe2x80x9d describes an unpowered, manually operated folding door for use with large, walk-in industrial refrigerators, freezers, and the like. The Reilly, Jr. et al. door is formed of a series of relatively rigid insulated panels which are interconnected by a corresponding series of flexible connectors. The Reilly, Jr. et al. door is laterally symmetrical, with identical numbers and widths of panels to each side of the center of the doorway. However, the various panels of each side assembly of the Reilly, Jr. et al. door are different widths from one another, and fold in opposite directions upon opening. No emergency opening system is provided, as there is no powered operation of the Reilly, Jr. et al. doors. In any event, they cannot both be opened by pushing upon their central frames, they swing in opposite directions from one another.
U.S. Pat. No. 5,097,883 issued.on Mar. 24, 1992 to James W. Robinson, titled xe2x80x9cFolding Shutter System,xe2x80x9d describes a system comprising a large number of extruded panels linked together along their vertical edges to provide an xe2x80x9caccordion foldxe2x80x9d type action. The Robinson assembly is adapted for use as a storm shutter system, and accordingly is not powered, as such systems are only infrequently closed and opened. Moreover, Robinson does not provide any means for emergency egress, as his shutters are adapted only for closure over a previously closed window or the like; they do not function as a closure for a doorway for normal traffic.
U.S. Pat. No. 5,109,911 issued on May 5, 1992 to Karlheinz Bockisch, titled xe2x80x9cAccordion Door,xe2x80x9d describes an asymmetrical door. system which opens only to one side of the door opening. Moreover, all panels are the same width and pivot about their vertical centerlines, including the panel remaining closest to the jamb when the door is opened. Accordingly, this panel cannot be hinged to the jamb, resulting in relatively low security for the Bockisch door assembly regardless of the materials from which it is made. Moreover, Bockisch does not provide any powered means for operating his door, and thus does not provide any form of manual override means for his door. Normally powered operation and manual override means are a part of the present bi-fold door invention.
U.S. Pat. No. 5,143,137 issued on Sept. 1, 1992 to Floyd D. West, titled xe2x80x9cOverlapping Seal For Insulated Folding Door,xe2x80x9d describes a door system closely related to the door system of the ""659 U.S. Patent to the same inventor, discussed further above. The door system of the ""137 U.S. Patent includes magnetic means for removably securing the adjacent panels together, rather than the breakaway ties or connectors used in the ""659 U.S. Patent. Otherwise, the same differences and distinctions noted further above in the discussion of the ""659 U.S. Patent, are see to apply here as well.
U.S. Pat. No. 5,152,332 issued on Oct. 6, 1992 to David Siener, titled xe2x80x9cMovable Wall System,xe2x80x9d describes a multiple folding panel system closely related to that disclosed in the Dixon et al. ""544 U.S. Patent discussed further above. The Siener system operates in much the same manner as the Dixon et al. system, using a motor to push the panels slightly toward their open positions in order to cause the hinge line to move slightly over center and xe2x80x9clockxe2x80x9d the panel array linearly. However, Siener requires an additional motor and mechanism which is initially activated when the panels are to be opened, with this additional motor and mechanism applying a xe2x80x9cbreakingxe2x80x9d force to push the hinges out of their locked alignment to allow the panels to be folded open. The present bi-fold door includes means for xe2x80x9cbreakingxe2x80x9d the panels from their fully aligned, coplanar configuration when initially opening the doors, but does so by means of an automatically operating mechanical linkage which initially xe2x80x9cbreaksxe2x80x9d the panels from their coplanar alignment and places them in non-parallel planes to allow them to fold for opening, rather than requiring a separate electric motor to accomplish this function.
U.S. Pat. No. 5,295,527 issued on Mar. 22, 1994 to Floyd D. West, titled xe2x80x9cFolding Door System,xe2x80x9d describes another multiple panel folding door adapted for use with loading docks and the like. The folding door of the ""527 West U.S. Patent is a continuation of the application which resulted in the ""137 U.S. Patent to the same inventor, discussed further above. The differences between the ""137 and ""527 West U.S. Patent are relatively minor, with both patents disclosing plural folding slats secured to one another by magnetic means. Accordingly, the same differences and distinctions between the present invention and the ""137 U.S. Pat. to West, are seen to apply here as well.
U.S. Pat. No. 6,098,695 issued on Aug. 8, 2000 to James P. Schwingle, titled xe2x80x9cStabilizer Arm For A Folding Door,xe2x80x9d describes a multiple panel door system wherein the lintel member containing the guide and drive means comprises a relatively heavy I beam. The drive means comprises a chain loop, with relatively thin drawbars between the chain and door actuating trolleys to pull and push the doors open and closed. Schwingle provides additional stabilizers which ride on the flanges of the I beams, to preclude bending of the drawbars due to arcuate movement of the door panels and compression on the drawbars. However, Schwingle does not disclose any means of opening his door manually in an emergency, as provided by the present bi-fold door. The panels of the Schwingle system are relatively flexible and are secured together only by a series of rings and grommets. Thus, they are easily deflected manually for passage therethrough without actuating the drive system.
British Patent Publication No. 531,417 accepted on Jan. 3, 1941 to the Educational Supply Association Limited, titled xe2x80x9cImprovements In And Relating To Folding And Sliding Doors, Partitions, And Windows,xe2x80x9d describes an asymmetrical system wherein all the panels fold to only one side of the door opening, unlike the laterally symmetrical system of the present invention. Moreover, all of the panels of the ""147 British Patent Publication fold to one side of the door frame (i. e., inside or outside), rather than the central panels being symmetrically disposed within the frame when folded, as in the present invention. No motorized actuation is disclosed in the ""417 British Patent Publication.
British Patent Publication No. 796,595 published on Jun. 18, 1958 to J. Avery and Co., titled xe2x80x9cImprovements Relating To Folding Doors,xe2x80x9d describes a multiple panel door system in which the door panels do not pull out completely when extended, but remain in an xe2x80x9caccordion foldxe2x80x9d state when the door is closed, unlike the present door system. The system of the ""595 British Patent Publication is asymmetrical, opening against only one side of the door frame, unlike the present laterally symmetrical system. No motor actuation means is disclosed in the ""595 British Patent Publication, and thus there is no motivation to provide a separate system for manual opening of the doors when power is removed, since no power actuating means is provided in the first place.
Finally, European Patent Publication No. 14,147 published on Aug. 6, 1980 to Bernard Chaumat et al. describes (according to the English abstract and drawings) an asymmetrical bi-fold door having a jamb panel slightly less than half the width of the primary panel. The two panels have a relatively complex double hinge connection to allow their completely adjacent and parallel folding, whereas the present system uses a single offset hinge to accomplish the same folding action. The device of the European Patent Publication is motorized, but uses cables wrapped about pulleys at the upper ends of the hinges, rather than trolley actuation as in the present door system. No means for manual emergency actuation is apparent in the ""147 European Publication.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.
The present bi-folding door provides two laterally symmetrical door assemblies to each side of the centerline of a door opening or frame. Each (left and right) door assembly comprises a pair of rigid panels, with the panel hingedly attached to the jamb edge of the door opening having a width substantially half that of the main panel. The two main panels are pivotally secured to upper drive mechanisms generally along their vertical centerlines, and abut one another along the vertical centerline of the doorway when the bi-folding door assembly is closed.
When the present bi-fold door assembly is opened, the two jamb panels swing about their hinge attachments to the lateral door jambs with their opposite edges moving arcuately to the inside of the structure with which the present door assembly is installed. The outwardly lateral edges of the main panels, i. e., those attached to the jamb panels, move inwardly due to their attachment to the jamb panels. The central edges of the two central panels thus swing outwardly relative to the building structure, due to their vertical centerline attachment to the drive mechanism.
The present invention also includes a mechanism for xe2x80x9cbreakingxe2x80x9d the doors from their coplanar alignment when closed, when the initial opening action is applied by means of the actuating motor. An arcuate cam track communicates with a roller at each drive trolley assembly, with drive force along the plane of the doors driving the rollers outwardly along their tracks and pivoting the central panels from the plane defined by the closed doors.
The present invention also includes means for manual opening, of the doors in the event of a power or drive failure, as required by law. As the central edges of the two central door panels swing outwardly during opening, a person(s) within the structure need only apply a force to the central edges of the central panels in the direction of egress from the structure, to cause the panels to swing open in their normally actuated manner. Sufficient force (on the order of twenty eight pounds or less) applied to the two abutting central edges of the central panels, overrides the mechanical advantage of the motor and speed reduction gearing to drive the actuating system in the direction of opening even though no power is applied to open the system. Thus, the present bi-folding door system remains intact at all times, with no mechanical disconnection of any components being required for manual operation of the doors in the event of a power failure.
When power is restored, the drive system automatically seeks the closed position, with a conventional detector (rotary wheel driven by the motor and optical sensor means, etc.) stopping the motor at the closed position. This same system also stops motion of the drive assembly when the door reaches its fully opened position. Conventional motion detector systems (infrared, threshold pressure plate, etc.) are also incorporated with the present bi-fold door system invention.
Accordingly, it is a principal object of the invention to provide a bi-folding door assembly comprising a total of four door panels, with two panels symmetrically disposed to each side of the center of the door opening.
It is another object of the invention to provide a bi-folding door assembly in which the two panels on each side of the doorway comprise a jamb panel hingedly attached to the jamb and a central panel hingedly attached to its respective jamb panel, with the two central panels each having a width substantially twice that of the jamb panels and pivoting about their vertical axes as they travel along the actuating track of the system.
It is a further object of the invention to provide a bi-folding door mechanism including an automated powered drive mechanism and means for manually opening the doors in the event of a power failure without requiring readjustment or reinstallation of any of the doors or components after such manual operation.
Yet another object of the invention is to provide a bi-folding door mechanism having mechanical means for automatically breaking the doors from their closed coplanar disposition during opening, and for aligning the doors in a coplanar disposition upon closing.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become apparent upon review of the following specification and drawings.